The minimal clinically important difference of the Southampton Dupuytren's Scoring Scheme

The minimal clinically important difference (MCID) for patient-reported outcome questionnaires is important in the interpretation of outcome in clinical and research settings. MCID represents the smallest difference in score that the patient would identify as important. There is, to our knowledge, no reported MCID value for Southampton Dupuytren's scoring scheme (SDSS). The SDSS is a 5-item 20 points scale, where 0 is considered no discomfort or physical limitations and 20 is the worst possible discomfort and physical limitations. The aim of this study was to determine the MCID for the SDSS. The study population consisted of 192 patients, in a prospective period from 2018 to 2021. All patients completed baseline SDSS questionnaires and again at 6 months follow-up with an external anchor question added. We calculated the mean change in scores of SDSS and used the anchor-based approach as well as a distribution-based method to calculate the MCID. At 6 months 163/192 (85%) of the patients were satisfied with the treatment according to the anchor question. In conclusion, the MCID of the SDSS for patients receiving treatment for DD is 1.5 points when estimated by an anchor-based approach and 1.62 points when estimated by a distribution-based approach. These MCID values should be considered in the interpretation of SDSS scores in the future, as well as when planning future studies on DD.